What is Janumet?
Janumet is a medicine that contains two active substances, sitagliptin and metformin hydrochloride. It is available as capsule-shaped tablets (pink: 50 mg of sitagliptin and 850 mg of metformin hydrochloride; red: 50 mg of sitagliptin and 1 000 mg of metformin hydrochloride).
What is Janumet used for?
Janumet is used in patients with type 2 diabetes to improve the control of blood glucose (sugar) levels. It is used as follows, in addition to diet and exercise:
• in patients who are not satisfactorily controlled on metformin alone (an antidiabetic);
• in patients who are already taking a combination of sitagliptin and metformin as separate tablets;
• in combination with a sulphonylurea, a PPAR gamma agonist such as a thiazolidinedione, or with insulin (another type of diabetes medicine) in patients who are not satisfactorily controlled on this medicine and metformin.
The medicine can only be obtained with a prescription.
How is Janumet used?
Janumet is taken twice a day. The strength of the tablet depends on the dose of the other antidiabetics previously taken by the patient. If Janumet is taken with a sulphonylurea or insulin, the dose of the sulphonylurea or insulin may need to be lowered to avoid hypoglycaemia (low blood sugar levels).
The maximum dose of sitagliptin is 100 mg per day. Janumet should be taken after meals to avoid stomach problems caused by metformin.
How does Janumet work?
Type 2 diabetes is a disease in which the pancreas does not make enough insulin to control the level of glucose in the blood or where the body is unable to use insulin effectively. Each of the active ingredients in Janumet, sitagliptin and metformin hydrochloride, has a different action.
Sitagliptin is a dipeptidyl-peptidase-4 (DPP-4) inhibitor. It works by inhibiting degradation
of "incretin" hormones in the body. These hormones, which are released after a meal, stimulate the pancreas to produce insulin. By increasing the level of incretins in the blood, sitagliptin stimulates the pancreas to produce more insulin when the blood sugar level is high, while it is ineffective when the blood glucose concentration is low. Sitagliptin also reduces the amount of glucose produced by the liver by increasing insulin levels and decreasing the levels of the hormone glucagon. Sitagliptin has been authorized in the European Union (EU) under the names Januvia and Xelevia since 2007 and under the name Tesavel since 2008.
Metformin basically inhibits the production of glucose and reduces its absorption in the intestine. Metformin has been available in the EU since the 1950s. The result of the combined action of the two active ingredients is a reduction in the level of glucose present in the blood. which helps control type 2 diabetes.
How has Janumet been studied?
Sitagliptin monotherapy as Januvia / Xelevia / Tesavel can be used with metformin and the combination of metformin and a sulphonylurea in patients with type 2 diabetes. The company presented the results of three studies of Januvia / Xelevia for support the use of Janumet in patients who were not satisfactorily controlled on ongoing metformin treatment. Two of the studies looked at sitagliptin in addition to metformin: the first compared it to placebo (a dummy treatment) in 701 patients and the second compared it to glipizide (a sulphonylurea) in 1,172 patients. The third study compared sitagliptin with placebo, when given as an add-on to glimepiride (another sulphonylurea), with or without metformin, in 441 patients.
The results of three additional studies were used to support the use of Janumet. The first included 1091 patients who were not satisfactorily controlled on diet and exercise alone and compared the effect of Janumet with that of metformin or sitagliptin. The second included 278 patients who were not satisfactorily controlled on the combination of metmorphine and rosiglitazone (a PPAR-gamma agonist) and compared the effects of adding sitagliptin or placebo. The third included 641 patients who were not satisfactorily controlled on stable insulin dosing, of whom three quarters were also taking metfomine. In this study, the effects of adding sitagliptin or placebo were also compared. In all studies, the main measure of effectiveness was the change in the concentration in the blood of a substance called glycosylated hemoglobin (HbA1c), which gives an indication. the effectiveness of blood glucose control.
The company carried out further studies to show that the active substances in Janumet are assimilated by the body in the same way as the two medicines given separately.
What benefit has Janumet shown during the studies?
Janumet was more effective than metformin alone. Adding 100 mg sitagliptin to metformin reduced HbA1c levels by 0.67% (from approximately 8.0%) after 24 weeks, compared with a 0.02% decrease in patients who had added a placebo. The efficacy of adding sitagliptin to metformin was similar to that of adding glipizide. In the study where sitagliptin was added to glimepiride and metformin, HbA1c levels decreased by 0.59% after 24 weeks, compared with an increase of 0.30% seen in patients adding a placebo.
In the first of three further studies, Janumet was more effective than metformin or sitagliptin alone. In the second study, HbA1c levels decreased by 1.03% after 18 weeks in patients adding sitagliptin to metformin and rosiglitazone, compared with a decrease of 0.31% in those adding placebo; finally, they decreased by 0. 59% after 24 weeks in patients who added sitagliptin to insulin, compared with a decrease of 0.03% in those who added placebo. There was no difference in this effect between patients also taking metformin and patients not taking it.
What is the risk associated with Janumet?
The most common side effect seen with Janumet (seen in 1 to 10 patients in 100) is nausea. For the full list of side effects reported with Janumet, see the package leaflet. Janumet must not be used in people who may be hypersensitive (allergic) to sitagliptin, metformin or any of the other ingredients. It must not be used in patients who have diabetic ketoacidosis or diabetic precoma (dangerous conditions that can occur with diabetes), kidney or liver problems, disorders that may affect the kidneys or a disease that causes reduced oxygen supply to the tissues such as heart or lung failure or a recent heart attack. It should also not be used in patients who consume excessive amounts of alcohol or who are suffering from alcoholism or in women who are breastfeeding. For the complete list of restrictions on use, see the package leaflet.
Why has Janumet been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Janumet's benefits are greater than its risks and recommended that it be given marketing authorization.
Other information about Janumet:
On July 16, 2008, the European Commission released to Merck Sharp & Dohme Ltd.
a "marketing authorization" for Janumet, valid throughout the European Union.
The marketing authorization is valid for five years and can be renewed after this period.
For the full version of Janumet's EPAR, click here.
Last update of this summary: 10-2009
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